The field of invention is U-shaped discharge lamps, such as U-shaped fluorescent lamps, an example being known by the trademark "Mod-U-Line" lamps.
U.S. Pat. No. 3,548,241 to Rasch discloses a U-shaped fluorescent lamp construction of the type having a support strap clamped around the ends of the lamp to improve its rigidity. The lamp does not employ a starting strip. Starting strips are conventionally provided on straight fluorescent lamps, for reducing their starting voltage. U.S. Pat. No. 2,683,836 to Lemmers discloses a narrow starting strip of conductive material carried on a straight lamp bulb. The starting strip can also be in the form of a coating, usually inside the bulb, of a transaprent conductor such as tin oxide, or stannous chloride as disclosed in U.S. Pat. No. 2,733,371 to Campbell. Conventional starting strips are difficult and time-consuming to apply to U-shaped lamps, and if applied prior to bending the bulb into a U-shape the strip is likely to break or develop high resistance when the bulb is bent.